Effective large scale irrigation of commercial crops is desirable in order to provide appropriate supply of water to these crops in a manner that requires minimal maintenance. Additionally, the precise supply of water to these crops whereby the crops receive an adequate amount of water sufficient for growth without receiving an over supply of water is desirable from an economic view point in environments where the supply of water is limited.
Furthermore, a very popular way of home gardening in today's world is through the use of potted plants. Pots provide the ability for people to enjoy gardening without having an actual garden. A problem that is faced by people when they leave their home for holidays and business is the care of their pot plants. Pot plants required regular watering or the plant will perish.
Ideally, the supply of water to a plant is controlled in order that the water is supplied at the same rate that it is consumed by the plant. Furthermore, the water should be ideally supplied at a rate that compensates for the non-uniform consumption of water by the plant over the course of a day and indeed over differing seasons. Additionally, different soil types have different flow characteristics. As such, the supply of water to plants located in different soil type should, ideally, be supplied in a manner that compensates for these flow characteristics in order to achieve an ideal supply of water to the plant.
If a plant is supplied with water in excess of the plants requirements, the plant may be subject to disease and, for larger trees, the excessive moisture in the ground may result in an instability possibly causing the tree to fall. Furthermore, over supply of water is inefficient and, in areas of drought and the like, potentially expensive.
If a plant is supplied with an inadequate level of water, growth is obviously inhibited. Furthermore, if the supply of water cycles between over supply and inadequate supply, the optimal growth of the tree is inhibited.
Various devices have been provided in the art to facilitate the supply of water to plants.
GB 2315396 describes a device for watering a plant having a refillable water reservoir and a pipe in liquid communication with the water reservoir. The pipe has perforations that facilitate the flow of water from the pipe to soil surrounding the pipe. Unfortunately, the perforations in this device are susceptible to being clogged with dirt particles. Thus, the perforations may, over time, become completely sealed and hence ineffective at facilitating liquid flow from the pipe to the ground.
U.S. Pat. No. 5,148,628 describes an irrigation and percolation apparatus having a liquid-filled wall of flexible elongated tubing, the tubing optionally having perforations. The tubing is used as a reservoir wall around the base of a plant and water passes through the perforations to keep the soil moist at the base of the plant. Again, the perforations in this device are susceptible to being clogged with dirt particles.
U.S. Pat. No. 6,023,883 describes a drip irrigator having a flexible hose, a fill neck and at least one percolation opening in the bottom of the flexible hose to transmit the water from the hose to the roots of a tree. Yet again, the percolation openings can potentially become sealed with particles of dirt.
FR 2,576,177 describes a device for watering a potted plant having a flexible reservoir for containing water and a plurality of rigid porous members protruding downwardly from the reservoir and in liquid communication with the water in the reservoir. The rigid porous members are constructed from a ceramic material. The device is inconvenient to install as a hole needs to be dug for each rigid porous member. Further, rigid porous members are susceptible to breakage.
U.S. Pat. No. 4,117,631 describes a watering device having a formable container arranged in and conforming to a lower part of a pot, an elongated substantially vertically extending tubular neck and a wick extending from the container.
WO 90/00347 discloses an apparatus for irrigation comprising a tubular reservoir, an inlet pipe and one or more water soaking feet. The soaking feet optionally contain wicks for soaking and transmitting water from the tube to earth above the soaking feet. The tubular reservoir forming a closed loop and the wicks only soaking water above the tube resulting in inefficient flow of liquid. Additionally, the wicks are inserted into pre-manufactured hole and hence the wicks may only be fitted to the tube at these pre-manufactured hole locations.
AU 61006/69 discloses an apparatus for conveying water to a plant having a pipe, a means for connection to a water supply and a plurality of apertures in the pipe. Each aperture has a length of cord tightly fitted therein for conducting water from within the pipe and along the length of the cord to the roots. The cord passes through one aperture to within the pipe and exits out through a second aperture diametrically opposite the first aperture. As the diametrically opposite apertures are positioned halfway up the pipe there may be a situation where the cord within the pipe is not in contact with water and hence not able to effectively disperse water to the soil surrounding the pipe. Furthermore, the apparatus disclosed in AU 61006/69 provides for an uncontrolled dispersion of water to the soil.
A second embodiment is disclosed in AU 61006/69 wherein a circular container is positioned around a plant. The circular container contains liquid and has apertures in the bottom through which lengths of cord are fitted to feed the roots of the plant. The plant grows through a central tube in the container. Hence, the plant is not able to be moved if it grows too large for the central tube.
The above prior art irrigation apparatus are deficient in that they provided an uncontrolled supply of water to plants. This uncontrolled supply of water generally leads to cycling whereby the plant cyclically receives an over supply of water and an undersupply of water.